"Why would they enter a career in politics, why would the next generation want to ... when they'll be accused of these unsubstantiated slurs?"

By the time Plibersek had made the point that, "If you're a man seen alone [in Canberra] with a young woman now, the assumption is automatically to this rumour stuff. That's a real problem," it was clear the Barnaby question wasn't far away.

It came from an audience member, who challenged Ms Markson on why Mr Joyce didn't deserve the same level of privacy "surrounding his private life and offered the same courtesy you believe the targets of Michaelia Cash's rant does?"

"In the one instance with Michaelia Cash, she threatened to name young women who are the subject of rumour when nothing had been proven at all and they are not public figures. And it's not even true as far as I'm aware," Ms Markson said.

"In the other instance, you had the Deputy PM of the country ... who has conservative family values, has campaigned against same-sex marriage, has campaigned against a vaccine because it might make women more promiscuous, a Deputy PM who has left his wife and four daughters for a media adviser who is now pregnant.

"Not only that, but then authorised, so he signed off on the creation of new jobs for her with two politicians within his own party. While living for six months in a free rental from a National Party donor. The two things couldn't be more different."

Ms Markson said Mr Joyce, "when he was Deputy PM, deserved every ounce of scrutiny that we in the media apply to him. His family didn't and we were very respectful to his wife and his four daughters. We never once hassled them".

"In that role he deserved every ounce of scrutiny and politicians, when they go into this job, they know they need to be accountable to voters," she said.

#QandA if politics inspired us rather than slaughtering each other we might be more engaged.

Ms Shamsie said it was fair game "if you're going to make a big deal about being all 'family values', then you're setting yourself up for someone to come at you".

"It's very striking to me that in Britain Jeremy Corbyn's wife is never seen with him. They made a conscious effort that he's not going to do that. He's not going to use his marriage or wife, she will not hold his hand or make tea for interviewers or do anything of that sort.

"So if someone is doing that, if they're putting themselves forward in that way, then I'm afraid they are opening themselves up and their private life to scrutiny."

Host Tony Jones said the Joyce affair was the biggest political story of the year, but asked if, now that he has stepped down, is it time to leave him alone.

Ms Plibersek said while people have a right to their private lives, "they don't have a right to spend taxpayers' money in any way they choose without accounting for it. They don't have a right to fail to disclose gifts from donors, That's our [the Labor Party's] only interest.

"The Labor Party has not been interested in his personal life. I feel sorry for everybody involved," she added, suggesting now might be the time for Barnaby to stop giving interviews.

A LOW THING TO DO

Mr Di Natale said it was time to give the "family or families in a very difficult situation time to process what's happened". But he was astounded at Mr Joyce's weekend "grey area" of paternity revelations.

"I have to say, having read his comments over the weekend, I was lost for words," he said.

"I thought it was a particularly low thing to do, to accuse somebody of that.

"And at this point I think there's the welfare of former staffer, family with four kids, a child and I think we should just let them get on and sort out what is a very difficult situation."